Plate manufacturing method and apparatus and plate

ABSTRACT

It is possible to continuously obtain, through simple steps, a plate which can gain sufficient strength, which is very lightweight and easy to handle, and which has the optimal heat insulating effect. A plate  1  is manufactured by: guiding a glass fiber containing member  5  into a space formed by an outer mold  11  and a center mold  12;  injecting a resin  4  into the space formed by the outer mold  11  and the center mold  12;  integrating the resin  4  with the glass fiber containing member  5  to form a hollow panel  2;  and injecting a foaming material into a hollow part formed in the hollow panel  2,  and causing the foaming material to foam and integrate with the hollow panel  2.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a method for manufacturing a plate which is used in various fields as a building wall, partition, floor or door, load-carrying platform, vehicle floor or wall, container, structural panel, and so on. This invention also relates to an apparatus for manufacturing such plate, and to the plate itself.

[0003] 2. Description of the Related Art

[0004] Examples of plates which have been used as building walls, partitions, doors, structural panels, or the like, include foamed plates manufactured by causing urethane resin or other material to foam, and plates (FRP) made by forming glass fibers around the outer surface of plywood or foamed plate as a core. Since these plates are lightweight, comparatively inexpensive, and easy to handle, they are widely used. However, their drawback is that they are weak. Accordingly, the problem is that these plates cannot be used in places where strength is required.

[0005] Therefore, recently, in order to keep the plates lightweight and to improve the strength, a plate is used which is structured in such a manner, for example, that a honeycomb made of paper, aluminum, or other materials is used as a core, and an aluminum plate is pasted to the surface and back of the honeycomb. A plastic adhesive is used to paste the aluminum plate to the honeycomb. The problems of this conventional plate are that the steps of manufacturing the honeycomb are complicated, and it is difficult to produce the honeycomb continuously, and the adhesive for pasting the aluminum plate to the honeycomb is expensive.

[0006] Accordingly, the applicant of the present invention suggests, in the Japanese Patent Laid-Open (Kokai) Publication No. H9-239878, the Japanese Patent Laid-Open (Kokai) Publication No. H9-286065, and the Japanese Patent Laid-Open (Kokai) Publication No. H11-93326, plates of which core is manufactured easily and at low cost, and the plates in which a flat plate is provided over the surface of the core, and methods for manufacturing such plates.

[0007] The Japanese Patent Laid-Open (Kokai) Publication No. H2-236347 discloses a method for manufacturing a structural panel, which comprises the steps of: putting together an upper mold and a lower mold which has a decorative surface member placed at its bottom; injecting a liquid material into a mold composed of the upper mold and the lower mold, and causing the liquid material to solidify and foam; and separating the upper mold from the lower mold immediately before shrinkage of the liquid material begins after the solidification.

[0008] Any of the plates described in the Japanese Patent Laid-Open (Kokai) Publication No. H9-239878, the Japanese Patent Laid-Open (Kokai) Publication No. H9-286065, and the Japanese Patent Laid-Open (Kokai) Publication No. H11-93326 is structured in such a manner that a flat plate is used as core for the purpose of reinforcement.

[0009] Regarding the method for manufacturing a structural panel as described in the Japanese Patent Laid-Open (Kokai) Publication No. H2-236347, as the apparatus becomes larger, the operation goes on intermittently while the foam reaction of the liquid material is caused and, therefore, there is a fear of impairing working efficiency.

SUMMARY OF THE INVENTION

[0010] It is an object of the present invention to improve the conventional methods and apparatus for manufacturing plates, and the conventional plates themselves.

[0011] In order to achieve this object, this invention provides a method for continuously manufacturing a plate, comprising: a guiding step of guiding a glass fiber containing member into a space formed by an outer mold and a center mold placed inside the outer mold and at a specified distance from the outer mold; a resin injecting step of injecting a resin into the space formed by the outer mold and the center mold; a hollow panel forming step of forming a hollow panel by integrating the resin with the glass fiber containing member; a foaming material injecting step of injecting a foaming material into a hollow part formed within the hollow panel; and an integrating step of causing the foaming material to foam and integrate with the hollow panel.

[0012] By this manufacturing method, it is possible to form a hollow panel continuously by integrating the resin with the glass fiber containing member and, at the same time, to cause the foaming material injected into the space within the hollow panel to foam. Accordingly, it is possible to continuously and easily manufacture the panel in which the hollow panel is integrated with the foamed body, without stopping the production line. When the foaming material is caused to foam, the hollow panel can serve as a mold for foaming. Therefore, it is unnecessary to prepare a separate mold for foaming.

[0013] The glass fiber containing member can have a plurality of roving threads and a sheet.

[0014] The panel forming step can include the step of wetting the glass fiber containing member with the resin by pressing the resin.

[0015] The temperature of the outer mold can be adjusted at a specified temperature.

[0016] The guiding step can include the step of guiding a print sheet with a desired picture image printed thereon to the outer surface of the glass fiber containing member, and the hollow panel forming step can include the step of integrating the print sheet, the glass fiber containing member, and the resin, thereby forming the hollow panel.

[0017] Addition of these steps makes it possible to make a desired picture image (including patterns, letters, pictures, and photographs) such as woodgrain, marble, or other patterns, or logos, on the surface of the plate at the same time as the manufacture of the plate.

[0018] The foaming material can be supplied from a plurality of supply ports and can be mixed immediately before injection into the center mold.

[0019] Moreover, the plate manufacturing method of this invention can further comprise a resin layer providing step of providing a resin layer over the surface of the hollow panel. This step makes it possible to form a uniform resin layer over the surface of the plate and to easily mirror-finish the surface of the plate.

[0020] The resin layer providing step can comprise the step of supplying a resin over the surface of the hollow panel and the step of rolling the supplied resin.

[0021] The foaming material can be injected at a temperature of 50° C. or lower; preferably at a temperature not higher than 30° C. and not lower than 20° C.; or more preferably at a temperature of approximately 25° C.

[0022] This invention also provides a plate manufacturing apparatus for continuously manufacturing a plate, comprising: a hollow panel forming device for forming a hollow panel, the device having an outer mold and a center mold placed inside the outer mold and at a specified distance from the outer mold; a guiding device for guiding a glass fiber containing member into a space formed by the outer mold and the center mold; a resin injecting device for injecting a resin into the space formed by the outer mold and the center mold; and a foaming material injecting device for injecting a foaming material into a hollow part formed within the hollow panel; and wherein the injected foaming material is caused to foam and integrate with the hollow panel.

[0023] This manufacturing apparatus makes it possible to form the hollow panel by integrating the resin with the glass fiber containing member and, at the same time, to cause the foaming material injected into the space within the hollow panel to foam. Accordingly, it is possible to continuously and easily manufacture the plate in which the hollow panel is integrated with the foamed body, without stopping the production line.

[0024] The glass fiber containing member can comprise a plurality of roving threads and a sheet.

[0025] The hollow panel forming device can include a pressure device capable of pressing the resin to wet the glass fiber containing member with the resin.

[0026] A thermostat for adjusting the temperature of the outer mold at a specified temperature can be connected to the outer mold.

[0027] The guiding device can include a print sheet guiding device for guiding a print sheet with a desired picture image printed thereon to the outer surface of the glass fiber containing member, and the hollow panel forming device can form the hollow panel by integrating the print sheet, the glass fiber containing member, and the resin.

[0028] The foaming material injecting device can comprise a plurality of supply ports for supplying the foaming material, and a mixing mechanism for mixing the foaming material supplied from the plural supply ports immediately before injection into the space formed within the hollow panel.

[0029] The plate manufacturing apparatus of this invention can further comprise a resin layer providing device for providing a resin layer over the surface of the hollow panel.

[0030] The resin layer providing device can comprise a supply device for supplying a resin over the surface of the hollow panel, and a rolling device for rolling the supplied resin.

[0031] The foaming material injecting device can comprise a temperature control device for controlling the temperature of the foaming material to be injected. This foaming material injecting device can control the temperature of the foaming material to be maintained at 50° C. or lower, preferably not higher than 30° C. and not lower than 20° C., or more preferably at approximately 25° C.

[0032] Moreover, this invention provides a plate manufactured by the method stated above.

[0033] This invention also provides a plate manufactured by the manufacturing apparatus stated above.

[0034] Furthermore, this invention provides a plate comprising a hollow panel formed by integrating a resin with a glass fiber containing member, and a foamed body filling the hollow panel.

[0035] The plate structured in the above-described manner can gain sufficient strength without using any reinforcing member such as honeycomb or rib in the hollow panel, and can be very lightweight and easy to handle. This foamed body can produce the optimal heat insulating effect and reduce resin consumption.

[0036] The glass fiber containing member includes a plurality of roving threads, and a glass fiber sheet.

[0037] A sheet with a desired picture image printed thereon can be further provided on the outer surface of the glass fiber sheet.

[0038] The surface of the plate may be mirror-finished.

BRIEF DESCRIPTION OF THE DRAWINGS

[0039]FIG. 1 is a sectional view of a plate according to Embodiment 1 of the present invention.

[0040]FIG. 2 is a perspective view of a part of the plate shown in FIG. 1.

[0041]FIG. 3 is a plan view of a manufacturing apparatus for manufacturing the plate of Embodiment 1 of this invention.

[0042]FIG. 4 is a side view of the manufacturing apparatus shown in FIG. 3.

[0043]FIG. 5 is an enlarged sectional view of a portion of the manufacturing apparatus shown in FIGS. 3 and 4.

[0044]FIG. 6 is an enlarged sectional view of a portion of the manufacturing apparatus shown in FIGS. 3 and 4.

[0045]FIG. 7 is an enlarged sectional view of a portion of the manufacturing apparatus shown in FIGS. 3 and 4.

[0046]FIG. 8 is a plan view illustrative of the state in which the plate obtained in Embodiment 1 of this invention is divided into blocks.

[0047]FIG. 9 is a plan view of a conveyance device according to another embodiment of this invention.

[0048]FIG. 10 is a right side view of the conveyance device according to another embodiment of this invention.

[0049]FIG. 11 is an enlarged sectional view of a portion of a manufacturing apparatus according to Embodiment 2 of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0050] Explanations are hereinafter given about the plate, the plate manufacturing method, and the plate manufacturing apparatus according to embodiments of the present invention with reference to the attached drawings.

Embodiment 1

[0051]FIG. 1 is a sectional view of a plate of Embodiment 1. FIG. 2 is a perspective view of a portion of the plate shown in FIG. 1.

[0052] As shown in FIGS. 1 and 2, a plate 1 of Embodiment 1 is composed of: a hollow panel 2 formed by integrating a resin 4 with a glass fiber containing member 5; and a foamed body 3 filling the hollow panel 2.

[0053] In both sides of the hollow panel 2 are formed concave portions 9A and 9B, each having a section substantially in the shape of the letter “U”. These concave portions 9A and 9B have the function to enable pipes, ribs, or the like, to serve as reinforcing materials to be inserted when the hollow panel 2 is connected with other hollow panels 2.

[0054] The glass fiber containing member 5 is composed by containing a plurality of roving threads 6, which are used, for example, as warp, and a glass fiber sheet 7 to reinforce the roving threads 6. The roving threads 6 are made by collecting about 4,000 strings of glass roving (approximately 24 μm in diameter). The glass fiber sheet 7 is formed by irregularly spreading and laminating coils which are made by binding glass fibers and which are further made spiral, and by pasting the spread and laminated spiral coils together with an adhesive. In Embodiment 1, this glass fiber sheet 7 is formed with a density of about 300 g/m³. On the outer surface of the glass fiber sheet 7 is provided a print sheet 8 on which a specified picture image (for example, woodgrain, marble, other patterns, or logos) is printed on the surface of a synthetic fiber sheet. Examples of the resin 4 include polyester resins. The resin 4 is applied to wet the glass fiber containing member and then solidifies, thereby forming the hollow panel 2.

[0055] The foamed body 3 is composed of a foaming material. There is no particular limitation on this foaming material. However, in Embodiment 1, an urethane resin is used as a principal component to compose the foaming material. A foam rate of any value for the foamed body 3 can be selected. However, in Embodiment 1, the foam rate is set at about 35 times the volume of the foamed body 3 before foaming.

[0056] With the plate 1 structured in the above-described manner, only the foamed body 3 is used as a reinforcing material for the hollow panel 2. Specifically speaking, it is possible to gain sufficient strength without using any reinforcing member, such as honeycomb or rib, in the hollow panel 2, and to significantly reduce the weight of the hollow panel 2. Also, this foamed body 3 can produce the optimal heat insulating effect and reduce resin consumption.

[0057] Since the print sheet 8 is provided on the surface, the plate 1 has an attractive appearance and compares favorably with, for example, polyester plywood.

[0058] A manufacturing apparatus for manufacturing the plate 1 of Embodiment 1 is hereinafter described with reference to the attached drawings.

[0059]FIG. 3 is a plan view of a manufacturing apparatus for manufacturing the plate of Embodiment 1. FIG. 4 is a side view of the manufacturing apparatus shown in FIG. 3. FIGS. 5 through 7 are enlarged sectional views of a portion of the manufacturing apparatus shown in FIGS. 3 and 4.

[0060] As shown in FIGS. 3 through 7, a manufacturing apparatus 10 of Embodiment 1 comprises: a hollow panel forming device 15 which has an outer mold 11 and a center mold 12 placed inside the outer mold 11 and at a specified distance from the outer mold 11; a guiding device 13 for guiding a glass fiber containing member 5 into a space formed by the outer mold 11 and the center mold 12; a resin injecting device 14 for injecting a resin 4 into the space formed by the outer mold 11 and the center mold 12; and a foaming material injecting device 16 for injecting a foaming material into the center mold 12; a conveyance device 17 for conveying the plate 1 in which the injected foaming material is caused to foam and integrate with the hollow panel 2; and a cutting device 18 for cutting the conveyed plate 1 in a desired length.

[0061] The outer mold 11 is used to define the external wall of the hollow panel 2 and has inlets 21 formed therein for injecting the resin 4. These inlets 21 are connected to the resin injecting device 14. The outer mold 11 is connected to a thermostat 27 for setting the outer mold 11 at a desired temperature. This thermostat 27 comprises a heating device (not shown in the relevant drawings) for heating the upstream side of the outer mold 11 to a desired temperature, and a cooling water circulating device (not shown in the relevant drawings) for cooling the downstream side of the outer mold 11 to a desired temperature.

[0062] The center mold 12 has a hollow shape and is used to define the inner wall of the hollow panel 2, and the foaming material injecting device 16 is provided in its hollow portion. This center mold 12 ends at a position slightly before the downstream end of the outer mold 11 (slightly off to the upstream side).

[0063] The guiding device 13 comprises: a plurality of winders 22 (for example, about 300 rolls) made by winding the aforementioned roving threads 6 without a bobbin to the diameter of about 27 cm and the height of about 25 cm; rolls 24 made by winding the aforementioned glass fiber sheet 7 in a roll form; rolls 25 made by winding the aforementioned print sheet 8 in a roll form; and yarn dividing machines 36 for guiding the roving threads 6.

[0064] The plural winders 22 are located on the furthest upstream side of the manufacturing apparatus 10. The yarn dividing machine 36 has a plurality of holes through which the roving threads 6 pass. The roving threads 6 go through the yarn dividing machines 6 and are then guided to the panel forming device 15. The rolls 24 and the rolls 25 are located adjacent to each other so that the print sheet 8 will be placed on the surface side (face-up) of the hollow panel 2 when the hollow panel 2 is formed.

[0065] To the resin injecting device 14 is connected a pressure device 26 capable of pressing the resin 4 through the inlets 21 of the outer mold 11. This pressing enables the resin 4 to effectively wet the glass fiber containing member 5 which has been guided to the space formed by the outer mold 11 and the center mold 12.

[0066] The foaming material injecting device 16 is composed of: foaming material injecting pipes 28, each of which is bifurcated substantially in the shape of the letter “U”; a mixing mechanism 29 which is placed at the upstream end of the center mold 12, which communicates with each of the foaming material injecting pipes 28, and mixes the supplied foaming material; and a temperature control device 48 for controlling the temperature of the foaming material to be injected from ends 30A and 30B of the foaming material injecting pipes 28.

[0067] As specifically shown in FIG. 5, the mixing mechanism 29 comprises a mixing screw 31 for adjusting the discharge amount and discharge pressure of the foaming material supplied from the ends 30A and 30B of the foaming material injecting pipes 28, and for mixing the foaming material supplied from both ends 30A and 30B. When the internal volume of the hollow panel 2 is secured to some degree and the internal volume of the moving hollow panel 2 almost coincides with the amount of the discharged foaming material, a pump (not shown in the relevant drawings) connected to the foaming material injecting pipe 28 adjusts the mixing amount by turning the mixing screw 31.

[0068] The temperature control device controls the temperature of the foaming material to be injected from the ends 30A and 30B of the foaming material injecting pipes 28 to be maintained at 50° C. or lower, preferably within the range of 20° C. to 30° C., or more preferably at approximately 25° C. It is possible to achieve a more appropriate foam rate by controlling the temperature of the foaming material when it is supplied as described above.

[0069] In Embodiment 1, the number of the foaming material injecting pipes 28 is three (that is, the foaming material injecting pipes 28 are located at three positions).

[0070] On the other hand, if the internal volume of the hollow panel 2 is small and the foaming material cannot always be discharged, it is possible to provide, at the foaming material injecting pipe 28, an injection amount adjusting valve 40 for adjusting the injection amount of the foaming material as shown in FIGS. 6 and 7. This injection amount adjusting valve 40 comprises a nozzle 41 in a substantially conical shape with a smaller diameter at its top, and a cylinder 42 in a substantially conical shape which is complementary to the top of the nozzle 41. The cylinder 42 moves back and forth so that when the cylinder 42 enters into the state shown in FIG. 6, the discharge of the foaming material is stopped. When the cylinder 42 enters into the state shown in FIG. 7, the foaming material is discharged. If the width and thickness of the hollow panel 2 are small, that is, if the foaming material is injected into the hollow panel 2 which has a small hollow volume, the foaming material is supplied intermittently from one end 30A (or 30B) in order to maintain the optimal foam rate of the foaming material. With the injection amount adjusting valve 40 structured as in FIGS. 6 and 7, it is possible to immediately stop the mixing of the foaming material supplied from both ends 30A and 30B. Accordingly, it is possible to provide a good foaming condition.

[0071] The conveyance device 17 is a conveyer-type device comprising wheels 32 and caterpillar belts 33 placed around the wheels in a movable manner. In this conveyance device 17, product compression slide sticks 37 and 38 for the caterpillar belts 33 are provided.

[0072] The cutting device 18 is composed of: a cutting saw 34; a movable rail 35 for supporting the cutting saw in a movable manner; and movable rails 39 for moving the cut plate 1.

[0073] Descriptions are hereinafter given about the method for manufacturing the plate 1 of Embodiment 1.

[0074] The roving threads 6 are first unreeled from the plural winders 22. The unreeled roving threads are divided by the yarn dividing machines 36 and are then guided into the space formed between the outer mold 11 and the center mold at the hollow panel forming device 15. At the same time, the glass fiber sheet 7 is unreeled from the rolls 24, and the print sheet 8 is unreeled from the rolls 25. At this time, they are unreeled so that the print sheet 8 will be placed over the surface of the hollow panel 2 upon the completion of the formation of the hollow panel 2. The unreeled glass fiber sheet 7 and print sheet 8 are, together with the plural roving threads 6, guided into the space formed between the outer mold 11 and the center mold 12.

[0075] As the roving threads 6, the glass fiber sheet 7, and the print sheet 8 are guided into the hollow panel forming device 15, the resin injecting device 14 is operated to inject the resin 4 from the inlets 21 formed in the top and bottom of the outer mold 11, thereby wetting the roving threads 6, the glass fiber sheet 7, and the print sheet 8. Since the outer mold 11 has been heated from its upstream side to its center part to a suitable temperature by the thermostat 27, the wettability of the resin 4 is enhanced and, therefore, the threads and sheets are wet in an optimal condition. Moreover, since the outer mold 11 has been cooled from its center part to its downstream side to a suitable temperature by the thermostat 27, the resin 4 hardens while the roving threads 6, the glass fiber sheet 7, and the print sheet 8 are continuously carried downstream, and the resin 4 integrates with the roving threads 6, the glass fiber sheet 7, and the print sheet 8, thereby forming the hollow panel 2.

[0076] Subsequently, at the same time as the hollow panel 2 is discharged out of the center mold 12, the foaming material injecting device 16 is operated to inject the foaming material into the hollow part of the hollow panel 2 by adjusting the mixing screw 31 so that the optimal foam rate will be attained. Alternatively, the foaming material is injected into the hollow part of the hollow panel 2 by adjusting the injection amount adjusting valve 40 so that the optimal foam rate will be attained. In Embodiment 1, adjustment is made so that the foam rate will be about 35 times the volume of the foamed body before foaming. The injected foaming material then begins to foam. When the foaming starts, the hollow panel 2 is still in the outer mold 11 and, therefore, foaming pressure generated by the foamed resin is then absorbed by the outer mold 11. However, from that time on, the hollow panel 2 takes over the role of the mold.

[0077] As described above, it is possible to manufacture the plate 1 continuously, without stopping each device.

[0078] The completed plate 1 is moved to the conveyance device 17, reaches the cutting device 18, and is cut by the cutting saw 34 into an arbitrary size. The cut plate 1 is carried by the movable rails 39 to a desired position.

[0079] In this way, the plate 1 is obtained which can increase in sufficient strength without using any reinforcing member, such as honeycomb or rib, in the hollow panel 2, and which is very lightweight and easy to handle. Moreover, the foamed body 3 can produce the optimal heat insulating effect and reduce the consumption of the resin 4, thereby reducing the cost of manufacturing.

[0080] Next, another plate 1 is manufactured in the same manner as described above, except that the foaming material injecting pipe 28 is set at one position. This plate 1 (42 mm thick, 865 mm wide, and 1980 mm long) is divided into blocks as shown in FIG. 8. The density of the foamed body 3 in the respective blocks (1 to 8) is measured. Table 1 shows the results of measurement.

TABLE 1

[0081] Referring to Table 1, it is confirmed that the foamed body which has foamed uniformly can be obtained even when the foaming material is injected at one position.

[0082] Regarding Embodiment 1, explanations have been given about the case in which the glass fiber sheet 7 and the print sheet 8 are used. However, without limitation to such case, the print sheet 8 should not necessarily be provided.

[0083] Moreover, regarding Embodiment 1, explanations have been given about the case in which the glass fiber containing member 5 is composed of the roving threads 6 and the glass fiber sheet 7. However, without limitation to such composition, the glass fiber containing member 5 may be composed, for example, by using roving threads as both warp and woof or by using sheets only, and its composition can be decided arbitrarily.

[0084] As the conveyance device, a roll-type device as shown in FIGS. 9 and 10 may be used. As illustrated in FIGS. 9 and 10, this conveyance device 170 comprises: a plurality of lower rolls 171 positioned in parallel with each other from the upstream side to the downstream side as supported by a support base 173; a plurality of upper rolls 172 positioned respectively in opposition to the respective lower rolls 171; a motor (not shown in the drawings) for rotating and driving the lower rolls 171 and the upper rolls 172; and a transmission 174 for changing the rotational speed of the lower rolls 171 and the upper rolls 172.

[0085] The lower rolls 171 and the upper rolls 172 are positioned with a specified space between them. The plate 1 is guided into this space, and is then held between the lower rolls 171 and the upper rolls 172 and carried from the upstream side to the downstream side by means of rotations of the lower rolls 171 and the upper rolls 172.

[0086] This conveyance device 170 is particularly suitable for the manufacture of, for example, a thin and wide plate. Specifically speaking, since the foaming material is injected in an amount slightly larger than the actual volume of the hollow panel 2, the foaming material expands and sometimes tends to affect the size (particularly the thickness) of the hollow panel 2. However, as the conveyance device 170 carries the plate 1 under pressure by means of the lower rolls 171 and the upper rolls 172, it is possible to retain the size accuracy with regard to the thickness of the plate 1.

[0087] Moreover, since the conveyance device 170 can control the rotational speed by using the transmission 174, it is possible to change the conveyance speed of the plate 1 as desired. Furthermore, since the number of the lower rolls 171 and the upper rolls 172 can be changed as necessary, it is possible to adjust the conveyance speed and distance of the plate 1, and the foaming completion time of the foaming material. For example, if the conveyance speed is comparatively fast, the number of the lower rolls 171 and the upper rolls 172 is increased so that the foaming of the foaming material can be finished while the plate 1 is positioned between the lower rolls 171 and the upper rolls 172.

Embodiment 2

[0088] Explanations are hereinafter given about a method and apparatus for manufacturing a plate of Embodiment 2 of this invention.

[0089]FIG. 11 is an enlarged sectional view of a portion of a manufacturing apparatus of Embodiment 2 in the vicinity of its outer mold. In Embodiment 2, the same reference numerals are given to the members similar to those described in Embodiment 1, and any detailed description thereof is omitted.

[0090] A manufacturing apparatus 100 of Embodiment 2 is different from the manufacturing apparatus 1 of Embodiment 1 in that a resin layer providing device 110 is provided on the downstream side of the outer mold 11. As shown in FIG. 11, this resin layer providing device 110 comprises grooves 14, each having a substantially triangular section, as resin supply parts for supplying a resin over the surface of the hollow panel, and rolling rolls 102 for rolling the supplied resin.

[0091] The grooves 104 are formed inside and on the downstream side of the outer mold 11 so that they are opposed to the top and bottom faces of the hollow panel 2. These grooves 104 are provided in such a manner that the bottoms of their substantially triangular sections are opposite the surface of the hollow panel 2. In the top (or ridge) of the groove 104, a plurality of resin supply holes 106 are made with some spaces between them along the lengthwise direction of the groove 104. The respective resin supply holes 106 are connected to a resin tank 105, from which the resin is supplied into the groove 104.

[0092] The rolling rolls 102 are positioned adjacent to the outside of the downstream side of the outer mold 11 and in opposition to the top and bottom faces of the hollow panel 2.

[0093] At the same time as the hollow panel 2 is discharged out of the center mold 12, the manufacturing apparatus 100 comprising this resin layer providing device 110 first operates, by the operation similar to that in Embodiment 1, the foaming material injecting device 16 to inject the foaming material into the hollow panel 2 so that the optimal foam rate will be attained. When the hollow panel 2 reaches the grooves 104 in the outer mold 11, the resin is supplied from the resin tanks 105 through the resin supply holes 106 into the grooves 104. This resin is then applied uniformly from the bottoms of the grooves 104 to the surface of the hollow panel 2.

[0094] The hollow panel 2 with the resin applied thereon is then discharged out of the outer mold 11, and the rolling rolls 102 uniformly roll the resin, thereby providing uniform resin layers 101 over the surfaces of the hollow panel 2. In this way, it is possible to continuously manufacture the plate 1, the surfaces of which are mirror-finished by means of the resin layers 101, without stopping the respective devices.

[0095] The completed plate 1 is moved to the conveyance device (or conveyance device 170) in the same manner as in Embodiment 1, reaches the cutting device 18, and is then cut by the cutting saw 34 into an arbitrary size. The cut plate 1 is conveyed by the movable rails 39 to a desired position.

[0096] Examples of the resin applied by the resin layer providing device 110 for the mirror-finishing as described above include polyester resin and melanin resin, which can be selected as desired.

[0097] As described above, the present invention makes it possible to continuously obtain, through simple steps, the plate which can increase in sufficient strength without using any reinforcing member, such as honeycomb or rib, within the hollow panel, which is very lightweight and easy to handle, and which has the optimal heat insulating effect. Also, the use of the foamed body can reduce the resin consumption, thereby reducing the cost of materials. 

What is claimed is:
 1. A method for continuously manufacturing a plate, comprising: a guiding step of guiding a glass fiber containing member into a space formed by an outer mold and a center mold placed inside the outer mold and at a specified distance from the outer mold; a resin injecting step of injecting a resin into the space formed by the outer mold and the center mold; a hollow panel forming step of forming a hollow panel by integrating the resin with the glass fiber containing member; a foaming material injecting step of injecting a foaming material into a hollow part formed within the hollow panel; and an integrating step of causing the foaming material to foam and integrate with the hollow panel.
 2. The plate manufacturing method according to claim 1, wherein the glass fiber containing member has a plurality of roving threads and a sheet.
 3. The plate manufacturing method according to claim 1, wherein the panel forming step includes the step of wetting the glass fiber containing member with the resin by pressing the resin.
 4. The plate manufacturing method according to claim 1, wherein the temperature of the outer mold is adjusted at a specified temperature.
 5. The plate manufacturing method according to claim 1, wherein the guiding step includes the step of guiding a print sheet with a desired picture image printed thereon to the outer surface of the glass fiber containing member, and the hollow panel forming step includes the step of integrating the print sheet, the glass fiber containing member, and the resin, thereby forming the hollow panel.
 6. The plate manufacturing method according to claim 1, wherein the foaming material is supplied from a plurality of supply ports and is mixed immediately before injection into the center mold.
 7. The plate manufacturing method according to claim 1, further comprising a resin layer providing step of providing a resin layer over the surface of the hollow panel.
 8. The plate manufacturing method according to claim 1, wherein the resin layer providing step comprises the step of supplying a resin over the surface of the hollow panel and the step of rolling the supplied resin.
 9. The plate manufacturing method according to claim 1, wherein the foaming material is injected at a temperature of 50° C. or lower.
 10. The plate manufacturing method according to claim 1, wherein the foaming material is injected at a temperature not higher than 30° C. and not lower than 20° C.
 11. A plate manufacturing apparatus for continuously manufacturing a plate, comprising: a hollow panel forming device for forming a hollow panel, the device having an outer mold and a center mold placed inside the outer mold and at a specified distance from the outer mold; a guiding device for guiding a glass fiber containing member into a space formed by the outer mold and the center mold; a resin injecting device for injecting a resin into the space formed by the outer mold and the center mold; and a foaming material injecting device for injecting a foaming material into a hollow part formed within the hollow panel; wherein the injected foaming material is caused to foam and integrate with the hollow panel.
 12. The plate manufacturing apparatus according to claim 11, wherein the glass fiber containing member comprises a plurality of roving threads and a sheet.
 13. The plate manufacturing apparatus according to claim 11, wherein the hollow panel forming device includes a pressure device capable of pressing the resin to wet the glass fiber containing member with the resin.
 14. The plate manufacturing apparatus according to claim 11, wherein a thermostat for adjusting the temperature of the outer mold at a specified temperature is connected to the outer mold.
 15. The plate manufacturing apparatus according to claim 11, wherein the guiding device includes a print sheet guiding device for guiding a print sheet with a desired picture image printed thereon to the outer surface of the glass fiber containing member, and the hollow panel forming device integrates the print sheet, the glass fiber containing member, and the resin, thereby forming the hollow panel.
 16. The plate manufacturing apparatus according to claim 11, wherein the foaming material injecting device comprises a plurality of supply ports for supplying the foaming material, and a mixing mechanism for mixing the foaming material supplied from the plural supply ports immediately before injection into the space formed within the hollow panel.
 17. The plate manufacturing apparatus according to claim 11, further comprising a resin layer providing device for providing a resin layer over the surface of the hollow panel.
 18. The plate manufacturing apparatus according to claim 17, wherein the resin layer providing device comprises a resin supplying device for supplying a resin over the surface of the hollow panel, and a rolling device for rolling the supplied resin.
 19. The plate manufacturing apparatus according to claim 11, wherein the foaming material injecting device comprises a temperature control device for controlling the temperature of the foaming material to be injected.
 20. The plate manufacturing apparatus according to claim 19, wherein the foaming material injecting device controls the temperature of the foaming material to be maintained at 50° C. or lower.
 21. The plate manufacturing apparatus according to claim 19, wherein the foaming material injecting device controls the temperature of the foaming material to be maintained not higher than 30° C. and not lower than 20° C.
 22. A plate manufactured by a plate manufacturing method comprising: a guiding step of guiding a glass fiber containing member into a space formed by an outer mold and a center mold placed inside the outer mold and at a specified distance from the outer mold; a resin injecting step of injecting a resin into the space formed by the outer mold and the center mold; a hollow panel forming step of forming a hollow panel by integrating the resin with the glass fiber containing member; a foaming material injecting step of injecting a foaming material into a hollow part formed within the hollow panel; and an integrating step of causing the foaming material to foam and integrate with the hollow panel.
 23. A plate manufactured by a plate manufacturing apparatus comprising: a hollow panel forming device for forming a hollow panel, the device having an outer mold and a center mold placed inside the outer mold and at a specified distance from the outer mold; a guiding device for guiding a glass fiber containing member into a space formed by the outer mold and the center mold; a resin injecting device for injecting a resin into the space formed by the outer mold and the center mold; and a foaming material injecting device for injecting a foaming material into a hollow part formed within the hollow panel; wherein the injected foaming material is caused to foam and integrate with the hollow panel.
 24. A plate comprising: a hollow panel formed by integrating a resin with a glass fiber containing member; and a foamed body filling the hollow panel.
 25. The plate according to claim 24, wherein the glass fiber containing member includes a plurality of roving threads, and a glass fiber sheet.
 26. The plate according to claim 25, wherein a sheet with a desired picture image printed thereon is further provided on the outer surface of the glass fiber sheet.
 27. The plate according to claim 24, wherein the surface of the plate is mirror-finished. 